The present invention relates to a missile, in particular for combatting moving targets such as airplanes, helicopters or the like, in which several propulsion units are arranged one after the other along its longitudinal axis, as well as a method for controlling the thrust of such a missile.
A prior art missile is describe in German reference DE 27 36 547 C1.
For combatting aircraft, helicopters or the like in the direct shot method (LOS method), prior art missiles can accelerate to a maximum speed of up to Mach 2.5 with a short thrust impulse of approximately 2.5 seconds in duration.
In the LOS method, at the time of launch there is already visual contact with the target. If at the start it has already been switched to the target, a corresponding missile follows a flight path which in the simplest case can be described by the steering law of proportional navigation. For combatting flying targets with the NLOS method, that is, flying targets to which there exists no visual connection, for example, concealed helicopters, missiles having a seeker head are known that scan a seek area with the seeker head and turn onto a course to the target after target detection. The typical path of such a missile consists of a start phase, in which the missile climbs to seek altitude in a relatively steep path, a seek phase, in which the missile flies along a relatively flat path and the seeker head scans the seek area for possible targets, and a final approach run phase, in which a target is detected and the missile flies to the detected target, which as a rule lies well below the seek altitude. The image processing speed of the seeker head sets a limit for the speed of the missile during the seek phase, which for example can be in the range from Mach 1.0 to Mach 1.2. In combatting a target at close range (at a distance of about 1000 m to 1500 m from the launch point), the missile must in addition follow a relatively narrow path radius in order to move from the seek phase into the final approach phase. If the speed of the missile is too great, this radius can no longer be followed. An additional limit for the speed during the seek phase results from this.
Missiles provided for use in the LOS method have a disadvantageous profile for use in the NLOS method, since at close range their speed is too great for the required narrow path radius during the transition to the approach run, and at long range (at distances of about 6000 m or more from the launch point) the cross-acceleration capacity is too low due to the drop in speed. Conversely, the known missiles for the NLOS method cannot immediately after the start achieve the high speeds required for the LOS method, since they are designed for an acceleration to a comparatively low speed in the seek phase.
German reference DE 27 36 547 C1, discloses a rocket with several propulsion unit stages arranged one after the other that are successively burned. However, the speed after the start phase is thereby determined by the thrust force of the first propulsion unit, so that the disadvantage remains that this speed is either too small for use in the LOS method or is too great for combatting targets at close range according to the NLOS method.
The aim of the present invention is to create a missile of the type named above that is suited both for combatting targets according to the LOS method and also for combatting targets at close range according to the NLOS method, as well as providing corresponding thrust regulation methods.
For the solution of this aim, it is inventively provided that in a missile of the type named above at least two propulsion units can be operated at the same time, and the missile comprises an ignition control means that can optionally ignite these two propulsion units simultaneously or successively.
According to the present invention, the thrust profile can be varied both with respect to the strength of the thrust and also with respect to the temporal course of the thrust. This makes it possible to use the same missile both in the LOS method and in the NLOS method. Before the launch, an item of information is inputted to the ignition control means concerning whether the missile is used in the LOS or the NLOS method. If the LOS method is selected, the ignition control means ignites the propulsion units simultaneously or shortly after one another. If the NLOS method is selected, the ignition control means ignites the second propulsion unit corresponding to a stored ignition program, for example, when the target is detected or after a predetermined time. Several ignition programs of this type, matched to different types of use and target types, can be stored in the ignition control means. The ignition program relevant for the respective use is selected before launching or is determined automatically by the missile on the basis of seeker head information. For the use in the NLOS method for combatting targets at close range, it is for example, not absolutely necessary to ignite an additional propulsion unit, as long as a sufficient speed is given when the target is detected. However, an additional acceleration in the final approach phase by means of an additional propulsion unit is advantageous for the improvement effect in the target. If no target detection ensues, the seek area can be enlarged by the ignition of an additional propulsion unit during the seek phase.